$ { {-2} \times \left[\begin{array}{rr}{-1} & {0} \\ {1} & {-2} \\ {1} & {3}\end{array}\right] = {?} } $
Answer: To multiply a matrix by a number, multiply each item of the matrix by the number. ${\left[\begin{array}{rr}{-2}\times{-1} & {-2}\times{0} \\ {-2}\times{1} & {-2}\times{-2} \\ {-2}\times{1} & {-2}\times{3}\end{array}\right]}$ Now, simplify: ${\left[\begin{array}{rr}{2} & {0} \\ {-2} & {4} \\ {-2} & {-6}\end{array}\right]}$